Hydroxyurea,a natural metabolite and an intermediate in d-cycloserine biosynthesis in streptomyces garyphalus

It was found that hydroxyurea, l-arginine and l-citrulline respectively significantly stimulated the formation of d-cycloserine in Streptomyces garyphalus. The formation of ¹⁴C]-hydroxyurea by washed cells was demonstrated after incubation with l-guanido-¹⁴C]-arginine and l-ureido-¹⁴C]-citrulline. The ¹⁵N of H₂NCO¹⁵NHOH was incorporated to 40% in d-cycloserine. The mass spectrum as well as the ¹⁵N NMR spectrum of labelled N,2-dicarbobenzyloxy-d-cycloserine derived from ¹⁵N]-hydroxyurea showed that hydroxyurea was the source of the heterocyclic nitrogen in the biosynthesis of d-cycloserine.